There are currently in use ski boots and in-line roller skates whose extension of the shell may be slightly modified by the user, for example for better adapting to his/her particular morphological characteristics, or for allowing to provide a size change per being worn by a plurality of users having feet of different sizes.
Such boots and in-line skates usually comprise a shell, provided in rigid or semi-rigid material, constituted by a front portion, extending at the region of the forefoot, and by a contiguous rear portion, extending at the region of the heel, whose mutual distance may be modified by the user by means of appropriate adjustment means, so as to change the length of the shell.
To the shell there is in general associated an inner boot, removable therefrom, provided in soft material, adapted to increase the comfort-fit of the user.
A problem that arises when one wishes to obtain a size change consists in the fact that the inner boot must also be able to be deformed.
In this regard, EP-1 066 862 discloses an in-line skate with variable length provided with an inner boot whose length may in turn change, being constituted by a front portion, that substantially covers the toes of the user, and by a rear portion, that extends at the region from the plantar's arch up to the heel, mutually interconnected by a band provided in an elastically deformable material.
When the inner boot is in a rest position the band is non-deformed and has its minimum extension, which corresponds therefore to the condition of minimum length of the inner boot and of the shell.
In the case in which the length of the shell has been modified and is greater than that of the inner boot in the condition of minimum length, the deformability of the band allows the inner boot to adapt itself to the various sizes of the foot of the user.
Such inner boots of the known type have however a drawback: in fact the band of elastically deformable material tends to elastically return in its non-deformed condition, pulling the front portion towards the rear portion and exerting therefore a compression on the tip of the foot of the user, so as to compromise the comfort-fit.
Moreover, the band of elastically deformable material may, with use, lose its elastic characteristics and permanently deform, thus compromising the fit-comfort thereof.